A Voice amplifier circuit is an electronic amplifier that amplifies low-power audio signals such as the signal from a radio receiver or a microphone to a level that is strong enough for driving loudspeakers or headphones. Different kinds of sound systems such as sound reinforcement systems, public address, speech systems & musical instrument amplifiers like guitar amplifiers use different types of audio amplifiers. In this project. We will design a 10W Voice amplifier circuit using a TDA2003 audio amplifier IC.
TDA2003 is a general-purpose audio amplifier circuit IC for stereo or mono audio design circuits. This amplifier IC can output up to 3.5A current to drive speakers & can also handle high currents up to 5A for a shorter duration without any damage. It can also handle short circuits in both AC & DC rails without damaging itself. It has an operating voltage of 18V but can handle high voltages up to 28V. This makes it robust to be used in automotive audio designs such as car stereos.
Hardware Component
you will need the following parts to build this project
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Breadboard | – | 1 |
| 2. | Electrolytic Capacitor | 0uF, 470uF, 1000uF | 1, 1, 2 |
| 3. | Battery | 9v | 1 |
| 4. | Audio Amp IC | TDA2003 | 1 |
| 5. | Ceramic Capacitors | 100nF/63V, 1822pF | 1 |
| 6. | Resistor | 470Ω, 100Ω, 47Ω, 1Ω | 1 |
| 7. | Speaker | 4 ohm | 1 |
TDA2003 Pinout
| Pin No. | Pin name | Description |
| 1 | Non – Inverting Input | Non-inverting end (+ve) of Amplifier |
| 2 | Inverting Input | Inverting end (-ve) of Amplifier |
| 3 | GND | Connect to the ground of the circuit |
| 4 | OUT | Outputs the amplified signal |
| 5 | Supply Voltage | Supply voltage, Minimum 6V & Maximum 28V |
Circuit Diagram
Working Explanation
The heart of this circuit is a TDA2003 amplifier IC. Voice amplifiers are generally used to address a large group or audience. There are 2 stages to the operation of this circuit. The Preamp stage & the Amplifier stage. In the first stage, the audio input comes from the electret microphone. Here, a Capacitor (10μF) blocks the DC component, allowing the AC component to flow to the base of the transistor amplifier(2N3904). The transistor amplifies the weak AC audio signal and sends it to Pin 1 of the TDA23003 IC.
Now in the 2nd stage, the TDA2003 IC receives the input signal from the preamp stage. It further amplifies the audio signal and sends it to an audio transducer such as a loudspeaker
Applications
- Generally used in devices designed for people with deficiencies such as vocal chord damage & throat/voice problems.
- Commonly used in devices such as radio amplifiers & Speech amplifiers.
